Preclinical study of artificial red cells ; Neo Rgl Cells

本文观察了脂质体包裹血红蛋白新红细胞（NRC）对不可逆失血性休克的作用。以及用作部分和全部心肺分流术的灌注液。[失血性休克]方法：选用比格犬8只，体重10-13kg。以30 ml/min的速率从动脉中取出血液以诱导出血性休克，使收缩压低于60 mmHg。30分钟后，在无任何治疗的稳态下，以相同的速率输注NRC。这种替换重复了三次以上。为维持良好的循环，动物需要输注1.5倍于失血量的NRC。血液交换后，尽管输注低粘度NRC（小于全血粘度的1/3），但心脏指数不增加，血管阻力不降低。在此情况下，NRC使氧转运效率（OTE）平均从32.2%增加到43.1%，补偿了心输出量的减少，并促进了心输出量的增加。 关于我们 降低耗氧量。另一方面，红细胞不能使OTE增加15%以上，不能令人满意地向外周组织供氧。重度失血性休克时，即使输注低粘度NRC，血管阻力也不降低，心输出量也不增加。而NRC通过提高其氧转运效率来补偿心输出量的减少，满足氧需求。[部分体外循环（PCPB）] 10只成年杂种犬，体重9-11kg，在37 ℃下，用辊式泵进行非搏动性PCPB。NRC组6只，灌流液为NRC 500ml，羟乙基淀粉（HES）500ml，Meylon 40ml/L，甘露醇3ml/kg（20%）。对照组（4只动物），灌流液为羟乙基淀粉1000 ml，Meylon 40 ml/L，甘露醇3ml/kg（20%）。PCPB持续1小时。NRC组的血管阻力（RV）下降不到对照组VR的1/4。这种变化表明，其粘度低于红细胞（RBC）。NRC输送氧的能力是RBC的2倍以上，NRC降低血管阻力，增加心输出量，具有良好的氧转运能力。NRC适合作为两种PCPB的灌注液。【全体外循环（TCPB）】TCPB在去除57.1 - 73.3%自体血后开始，持续7小时。在TCPB期间使用NRC时，血管阻力（VR）降至使用红细胞（RBC）时VR的1/4。这种变化表明，NRC的粘度低于RBC的粘度，从而降低了循环系统的负荷。NRC输送的氧量高于RBC输送的氧量，导致NRC的耗氧量更大，TCPB中血清LDH水平低于RBC。因此，NRC弥补了稀释TCPB的氧转运能力下降的缺点，进一步增加了稀释TCPB的循环，进一步提高了循环改善率。

We evaluated the effects of liposome encapsulated homoglobin Neo Red Cell (NRC) on irreversible homorrhagicshock. and as a perfusate for partial and total cardiopulmonary bypass. [Homorrhagic shock] Methods : Eight beagles (body weight ; 10-13kg) were used. Blood was removed from the arteries at a rate of 30 ml/min to induce hemorrhagic shockbringing the systolic pressure lower than to 60 mmHg. After 30 minutes steady state without any treatment NRC was transfused at the same rate. This replacement repeated more than three times. To maintained the circulation satisfactory, the animal needed the 1.5 times amount of NRC transfusion to blood loss. After blood exchange, the cardiac index did not increase and vascular resistance did not decrease in spite of low viscosity NRC (less than 1/3 of that of whole blood) transfusion. In this situation, NRC increased the oxygentransport efficiency (OTE) averaged from 32.2 to 43.1%, compensated the reduction of cardiac output and contributed the incr … More easing the oxygenconsumption. On the other hand, red blood cell did not increase the OTE more than 15% and did not supply oxygen to peripheral tissue satisfactory. On severe hemorrhagic shock, even if transfused low viscosity NRC,vascular resistance did not decrease and cardiac output did not increase. However, NRC compensated reduction of cardiac output by increasing its oxygen transport efficiency and satisfied the oxygen demand. [Partial cardiopulmonary bypass (PCPB)] Nonpulsatile PCPB was made in 10 adult mongrel dogs weighing 9-11 kg at 37 Cusing a rollerpump. The perfusate was 500ml NRC,500 ml hydroxyethylstarch (HES), 40 ml/L Meylon, AND 3 ml/kg mannitol (20%) on NRC group (6 animals). The perfusate was 1000 ml HES,40 ml/L Meylon, and 3 ml/kg mannitol (20%) on controlgroup (4 animals). PCPB was continued for hour. Vascular resistance (RV) in NRC group decreased less than 1/4 of VR in control group. This change suggests that, the viscosity of which is lower than that red blood cells (RBC). NRC delivered oxygen more than two times of that of RBC.NRC reduced vascular resistance, increased cardiac output, and showed excellentoxygen transport ability. NRC is suitable as perfusate for both PCPB.[Total cardiopulmonary bypass (TCPB)] The TCPB was started after removal of 57.1-73.3% of autologous blood and continued for 7 hours. During TCPB using NRC,the vascular resistance (VR) decreased to 1/4 of VR when red blood cells (RBC) were used. This change suggests that NRC,the viscosity of which is lower than that of RBC,reduced the load on the circulation system. The oxygen volume delivered by NRC was higher than that delivered by RBC,resulting in a greater oxygen consumption with NRC.During TCPB,the serum LDH level was lower than that using RBC.So we concluded that NRC compensated for the reduction in the oxygen transport ability, which is a disadvantage of dilution TCPB,and further increased the circulation of dijution TCPB,and further increased the circulation improvin Less